1. Fields of the Invention
The present invention relates to an electric treadmill, and more particularly, to a device which is provided with a plurality of fixed sensing lines. When the operator touches one of them, a command is given to accelerate, decelerate or stop the operation of the treadmill.
2. Description of the Prior Art
First of all, it is noted that the present invention is continuation-in-part of Ser. No. 09/247,571 filed Feb. 10, 1999 now U.S. Pat. No.6,126,575 and 09/467,224 filed Dec. 20, 1999 now U.S. Pat. No. 6,179,754 (hereinafter called “the first prior art” and “the second prior art”). It's described in the first prior art that an automatic roll-up rope is tied around the operator's body. In addition, a sensor is disposed to detect the position of the runner. After a central processing unit processes the detection parameters, a command is given to accelerate or decelerate the motor.
The second prior art describes that a detector is fitted to both sides of the tread base for detecting the position of the runner. After a central processing unit processes the detection parameters, a command is given to accelerate or decelerate the motor.
In brief, the central processing units of both prior arts are used to evaluate the detection parameters to obtain the exact position of the runner. Thereafter, a command is given to accelerate or decelerate the motor. Consequently, the motor reacts after the steps of the runner or the body displacement. Although both prior arts can obtain more accurate parameters to give command for accelerating or decelerating the motor, this is the reason why difficulties are caused in programming and in cooperation with other components. Therefore, the production costs thereof are considerably increased and the price thereof is always kept in a high level.